The technology of multiple layer structures is known for creating interferential effects on optical surfaces.
In the field of ophthalmic lenses, it is usual to use interferential multiple layer structures to create anti-reflective or reflective surfaces of different intensities and residual colors, usually anti-reflective of green color with visible light reflection percentages lower than 2.5%, or even lower than 1.5% for each surface including a multiple layer structure.
Also known is the use of treatments for filtering a percentage of the IRA (infra-red A) or blue radiation selectively. However, the IR light filtering requires complex solutions that are not easily applicable to transparent lenses without coloring. In particular, layers of metals can be applied that absorb or help to reflect part of the IRA radiation but these materials absorb at the same time visible light, and so they do not enable obtaining high visible transmittance lenses with these features.
Interferential filters exist (for example the ones of the heat mirror type) that are used in applications for precision optics on a mineral lens, and they enable reducing the IRA radiation transmittance while maintaining a high visible transmittance: these filters have a multiple layer structure with between 40 and 100 layers and they have a total thickness over 1000 nm (nanometers), These filters are designed specifically for a certain angle of incidence of the incident radiation, and therefore if the angle varies, they display the typical effects of iridescence. Also, these treatments usually have a slight residual coloring which, in comparison with the anti-reflective lenses, makes them rather unattractive in aesthetic terms.